Project Summary/Abstract: Hypertension is a known risk factor for heart failure, kidney failure, stroke, and myocardial infarction. The prevalence of hypertension is substantially higher among African American adults (40.3%), compared to Whites (27.8%) and Hispanics (27.8%). Consequently, African Americans have high rates of stroke, congestive heart failure, and end-stage renal disease. To reduce this disparity, there is a critical need to identify the contextual factors contributing to these disparities experienced by African Americans. The role of marriage in protecting against diseases and improving well-being is well-established in the literature. Married individuals have a lower prevalence of morbidity and mortality than those who are unmarried. The social causation theory posits that mechanisms, such as behavioral and psychological health, mediate partially the association between relationship status and health outcomes. However, it is unclear if health risk behaviors differ between married and cohabiting (live with partner in a marriage-like relationship) adults. Previous studies tended to combine married and living with partner as a single category, which may mask the heterogeneity in health risk behaviors across detailed relationship statuses and result in missed opportunities for targeted interventions. Given cohabitation is more common among African Americans for reasons unique to them (e.g., disproportionate incarceration, lack of exposure to married couples during childhood, and economic marginalization), cohabitation is a plausible contextual factor that could contribute to disparities in hypertension among African Americans. The purpose of this proposed research is to estimate the risk of developing hypertension among African American cohabitors. I will estimate the incidence of hypertension among cohabitors compared to those who are married. I will then examine the associations between relationship status (cohabiting vs married) and known risk factors for hypertension (tobacco/alcohol use, physical activity, perceived stress, perceived discrimination). Lastly, I will determine how hypertension incidence and the associations between cohabitation and known risks factors for hypertension differ between African American and White adults. The proposed aims will be measured over two data time points using two longitudinal cohort studies to assess replicability and accelerate the knowledge discovery in this research area. The innovation of this proposal is that the research will directly compare cohabitors against married adults, which is critical in gaining a better understanding of how relationship status influences health, especially among African Americans.